kubernetes master 节点包含的组件:
kube-apiserver :集群核心,集群API接口、集群各个组件通信的中枢;集群安全控制;
kube-scheduler: 集群调度器 ,根据node负载(cpu、内存、存储、策略等)将pod分配到合适node。
kube-controller-manager:集群状态管理器 。当集群状态与集群期望值不同时,该控制器会根据已有策略将其恢复到指定状态。
目前这三个组件需要部署在同一台机器上。
kube-scheduler、kube-controller-manager 和 kube-apiserver 三者的功能紧密相关;
注意:集群只能有一个 kube-scheduler、kube-controller-manager 进程处于工作状态,如果运行多个,则需要通过选举产生一个 leader
说明:当前master没有做高可用部署,后边优化补全高可用方案。
前期首先进行kubenetes v1.12.2相关服务命令部署
将下载的https://dl.k8s.io/v1.12.2/kubernetes-server-linux-amd64.tar.gz 解压(之前已经解压过),将服务相关的命令全都拷贝到/usr/local/bin/目录
cp -r server/bin/{kube-apiserver,kube-controller-manager,kube-scheduler,kubectl,kube-proxy,kubelet} /usr/local/bin/
一,配置和启动 kube-apiserver
1,创建 kube-apiserver的service配置文件
service配置文件/usr/lib/systemd/system/kube-apiserver.service内容:
[Unit] Description=Kubernetes API Service Documentation=https://github.com/GoogleCloudPlatform/kubernetes After=network.target After=etcd.service [Service] EnvironmentFile=-/etc/kubernetes/config EnvironmentFile=-/etc/kubernetes/apiserver ExecStart=/usr/local/bin/kube-apiserver \ $KUBE_LOGTOSTDERR \ $KUBE_LOG_LEVEL \ $KUBE_ETCD_SERVERS \ $KUBE_API_ADDRESS \ $KUBE_API_PORT \ $KUBELET_PORT \ $KUBE_ALLOW_PRIV \ $KUBE_SERVICE_ADDRESSES \ $KUBE_ADMISSION_CONTROL \ $KUBE_API_ARGS Restart=on-failure Type=notify LimitNOFILE=65536 [Install] WantedBy=multi-user.target
2,/etc/kubernetes/config文件的内容为:
# kubernetes system config # The following values are used to configure various aspects of all # kubernetes services, including # # kube-apiserver.service # kube-controller-manager.service # kube-scheduler.service # kubelet.service # kube-proxy.service # logging to stderr means we get it in the systemd journal KUBE_LOGTOSTDERR="--logtostderr=true" # journal message level, 0 is debug KUBE_LOG_LEVEL="--v=0" # Should this cluster be allowed to run privileged docker containers KUBE_ALLOW_PRIV="--allow-privileged=true" # How the controller-manager, scheduler, and proxy find the apiserver KUBE_MASTER="--master=http://10.1.14.21:8080"
这个配置文件是全局配置文件,上述有提示:该配置文件同时被kube-apiserver、kube-controller-manager、kube-scheduler、kubelet、kube-proxy使用。
3,apiserver配置文件/etc/kubernetes/apiserver内容为:
### ## kubernetes system config ## ## The following values are used to configure the kube-apiserver ## # ## The address on the local server to listen to. KUBE_API_ADDRESS="--advertise-address=10.1.14.21 --bind-address=10.1.14.21 --insecure-bind-address=10.1.14.21" # ## The port on the local server to listen on. #KUBE_API_PORT="--port=8080" # ## Port minions listen on #KUBELET_PORT="--kubelet-port=10250" # ## Comma separated list of nodes in the etcd cluster KUBE_ETCD_SERVERS="--etcd-servers=https://10.1.14.23:2379,https://10.1.14.24:2379,https://10.1.14.22:2379" # ## Address range to use for services KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16" # ## default admission control policies KUBE_ADMISSION_CONTROL="--admission-control=ServiceAccount,NamespaceLifecycle,NamespaceExists,LimitRanger,ResourceQuota" # ## Add your own! KUBE_API_ARGS="--authorization-mode=RBAC --runtime-config=rbac.authorization.k8s.io/v1beta1 --kubelet-https=true --enable-bootstrap-token-auth --token-auth-file=/etc/kubernetes/token.csv --service-node-port-range=30000-32767 --tls-cert-file=/etc/kubernetes/ssl/kubernetes.pem --tls-private-key-file=/etc/kubernetes/ssl/kubernetes-key.pem --client-ca-file=/etc/kubernetes/ssl/ca.pem --service-account-key-file=/etc/kubernetes/ssl/ca-key.pem --etcd-cafile=/etc/kubernetes/ssl/ca.pem --etcd-certfile=/etc/kubernetes/ssl/kubernetes.pem --etcd-keyfile=/etc/kubernetes/ssl/kubernetes-key.pem --enable-swagger-ui=true --apiserver-count=3 --audit-log-maxage=30 --audit-log-maxbackup=3 --audit-log-maxsize=100 --audit-log-path=/var/lib/audit.log --event-ttl=1h"
配置文件说明:
–experimental-bootstrap-token-auth Bootstrap Token Authentication在1.9版本已经变成了正式feature,参数名称改为–enable-bootstrap-token-auth
如果中途修改过–service-cluster-ip-range地址,则必须将default命名空间的kubernetes的service给删除,使用命令:kubectl delete service kubernetes,然后系统会自动用新的ip重建这个service,不然apiserver的log有报错the cluster IP x.x.x.x for service kubernetes/default is not within the service CIDR x.x.x.x/16; please recreate
–authorization-mode=RBAC 指定在安全端口使用 RBAC 授权模式,拒绝未通过授权的请求;
kube-scheduler、kube-controller-manager 一般和 kube-apiserver 部署在同一台机器上,它们使用非安全端口和 kube-apiserver通信;
kubelet、kube-proxy、kubectl 部署在其它 Node 节点上,如果通过安全端口访问 kube-apiserver,则必须先通过 TLS 证书认证,再通过 RBAC 授权;
kube-proxy、kubectl 通过在使用的证书里指定相关的 User、Group 来达到通过 RBAC 授权的目的;
如果使用了 kubelet TLS Boostrap 机制,则不能再指定 –kubelet-certificate-authority、–kubelet-client-certificate 和 –kubelet-client-key 选项,否则后续 kube-apiserver 校验 kubelet 证书时出现 ”x509: certificate signed by unknown authority“ 错误;
–admission-control 值必须包含 ServiceAccount;
–bind-address 不能为 127.0.0.1;
runtime-config配置为rbac.authorization.k8s.io/v1beta1,表示运行时的apiVersion;
–service-cluster-ip-range 指定 Service Cluster IP 地址段,该地址段不能路由可达;
缺省情况下 kubernetes 对象保存在 etcd /registry 路径下,可以通过 –etcd-prefix 参数进行调整;
如果需要开通http的无认证的接口,则可以增加以下两个参数:–insecure-port=8080 –insecure-bind-address=127.0.0.1。注意,生产上不要绑定到非127.0.0.1的地址上
4,启动kube-apiserver
systemctl daemon-reload systemctl enable kube-apiserver systemctl start kube-apiserver systemctl status kube-apiserver
二,配置和启动 kube-controller-manager
1,创建 kube-controller-manager的serivce配置文件
文件路径/usr/lib/systemd/system/kube-controller-manager.service
[Unit] Description=Kubernetes Controller Manager Documentation=https://github.com/GoogleCloudPlatform/kubernetes [Service] EnvironmentFile=-/etc/kubernetes/config EnvironmentFile=-/etc/kubernetes/controller-manager ExecStart=/usr/local/bin/kube-controller-manager \ $KUBE_LOGTOSTDERR \ $KUBE_LOG_LEVEL \ $KUBE_MASTER \ $KUBE_CONTROLLER_MANAGER_ARGS Restart=on-failure LimitNOFILE=65536 [Install] WantedBy=multi-user.target
2,配置文件/etc/kubernetes/controller-manager
### # The following values are used to configure the kubernetes controller-manager # defaults from config and apiserver should be adequate # Add your own! KUBE_CONTROLLER_MANAGER_ARGS="--address=127.0.0.1 --service-cluster-ip-range=10.254.0.0/16 --cluster-name=kubernetes --cluster-signing-cert-file=/etc/kubernetes/ssl/ca.pem --cluster-signing-key-file=/etc/kubernetes/ssl/ca-key.pem --service-account-private-key-file=/etc/kubernetes/ssl/ca-key.pem --root-ca-file=/etc/kubernetes/ssl/ca.pem --leader-elect=true"
说明:
–service-cluster-ip-range 参数指定 Cluster 中 Service 的CIDR范围,该网络在各 Node 间必须路由不可达,必须和 kube-apiserver 中的参数一致;
–cluster-signing-* 指定的证书和私钥文件用来签名为 TLS BootStrap 创建的证书和私钥;
–root-ca-file 用来对 kube-apiserver 证书进行校验,指定该参数后,才会在Pod 容器的 ServiceAccount 中放置该 CA 证书文件;
–address 值必须为 127.0.0.1,kube-apiserver 期望 scheduler 和 controller-manager 在同一台机器;
3,启动 kube-controller-manager
systemctl daemon-reload systemctl enable kube-controller-manager systemctl start kube-controller-manager systemctl status kube-controller-manager
4,我们启动每个组件后可以通过执行命令kubectl get cs,来查看各个组件的状态;
[root@master01 kubernetes]# kubectl get cs NAME STATUS MESSAGE ERROR scheduler Unhealthy Get http://127.0.0.1:10251/healthz: dial tcp 127.0.0.1:10251: connect: connection refused controller-manager Healthy ok etcd-1 Healthy {"health": "true"} etcd-2 Healthy {"health": "true"} etcd-0 Healthy {"health": "true"}
查看kube-controller-manager正常,下边配置kube-scheduler
三,配置和启动 kube-scheduler
1,创建 kube-scheduler的serivce配置文件
文件路径/usr/lib/systemd/system/kube-scheduler.service
[Unit] Description=Kubernetes Scheduler Plugin Documentation=https://github.com/GoogleCloudPlatform/kubernetes [Service] EnvironmentFile=-/etc/kubernetes/config EnvironmentFile=-/etc/kubernetes/scheduler ExecStart=/usr/local/bin/kube-scheduler \ $KUBE_LOGTOSTDERR \ $KUBE_LOG_LEVEL \ $KUBE_MASTER \ $KUBE_SCHEDULER_ARGS Restart=on-failure LimitNOFILE=65536 [Install] WantedBy=multi-user.target
2,配置文件/etc/kubernetes/scheduler
### # kubernetes scheduler config # default config should be adequate # Add your own! KUBE_SCHEDULER_ARGS="--leader-elect=true --address=127.0.0.1"
说明:–address 值必须为 127.0.0.1,因为当前 kube-apiserver 期望 scheduler 和 controller-manager 在同一台机器;
3,启动kube-scheduler
systemctl daemon-reload systemctl enable kube-scheduler systemctl start kube-scheduler systemctl status kube-scheduler
4,验证 master 节点功能
[root@master01 kubernetes]# kubectl get cs NAME STATUS MESSAGE ERROR controller-manager Healthy ok scheduler Healthy ok etcd-1 Healthy {"health": "true"} etcd-0 Healthy {"health": "true"} etcd-2 Healthy {"health": "true"}
四,其他master节点部署
线上环境不止一个master,如果要高可用,一般都会是多个。 配置完一台master以后,其他master只需要把.kube、kube*二进制命令, kubectl kubeconfig 、/etc/kubenetes/配置文件 以及几个xxx.service配置文件(搞成enable)弄过来就行了。
当然高可用一般我们设置一个域名解析道slb或者alb,需要注意一点就是每个master节点最好将这个域名定向到master本地ip,免得出现回源回路情况。自建环境就考虑下代理了,nginx 4层代理或者haproxy都可以。
参考文章:部署master节点
转载请注明:21运维 » kubenetes 集群二进制安装之master安装部署